There are only three known reasons why this could occur.
i)The concrete mix design contained Type F fly ash or volcanic ash causing matrix lock up of calcium by the Pozzolanic reaction. The wrong concrete mix was utilised.
ii)Large cracks were present and the applicator did not tape the underside of cracks during application to ensure product flooding occured inside these cracks. A superficial seal was achieved and such cracks would require underside taping and re-treatment with Radcon.
iii) The most common crack leaking occurence would be on trafficable areas where maximum loading is causing structural failure due to working cracks breaking open. In this instance rainwater will reactivate and re-seal these cracks proving product efficacy.
With this said the Radcon system will break again and these working cracks will require routing out and an elastomeric material emplaced to accomodate movement and achieve an overall watertight result.